1. Field of the Invention
The invention relates to an image reading apparatus for reading an image of a document set on a setting board.
2. Related Background Art
In general, in this kind of apparatus, a document is set on the upside surface of a transparent setting board, and the document and the setting board is covered by a setting board cover, then light is emitted under the setting board toward the downside surface of the setting board, further the light is reflected by the setting board cover and the document and is received by a light receiving element which is installed under the setting board. Continuously, reflection light signals generated from the reflected light received by the light receiving element are converted into digital signals, and image data is obtained. In the case, in order to eliminate noise data caused by shadow around the document from the image data, with respect to the document region recognized as a rectangle, the image data without containing edge data is outputted (refer to patent document 1).    Patent document 1: Japan patent publication 2004-274198.
However, in the conventional image reading apparatus stated above, because the image data without containing edge data is outputted, there is a problem to be solved. That is, for example, in the case to print image data of a business card and the like on a paper bigger than the document (e.g. business card), when cutting off the bigger paper on which only an image without edge line is printed, it is difficult to correctly judge the edge of the business card.